1. Field of the Invention
The present invention relates to a method of unlocking the password-locked condition of a password-locking storage device of an information processor when the information processor resumes its normal operating condition from its power saving mode. The invention concerns also an information processor to which the method is applied and a computer-readable recording medium in which a program for executing the method is stored.
2. Description of the Related Art
In computer systems such as information processors, e.g., personal computers, some of various types of hard disks to be used as memories have a password lock function that prohibits access to data on the hard disk by setting a password.
If a password is set in the password-locking hard disk, the hard disk assumes a password-locked condition when supply of power is connected to the computer so that access to data stored on the hard disk is not possible until the password-locked condition is unlocked by inputting the same password.
Assuming that supply of power is again connected to a password-locking hard disk after once disconnected for any cause, e.g., when the hard disk is removed from the computer system, the hard disk will be in password-locked condition so that it is inhibited from having access to data stored on the hard disk until this password-locked condition has been unlocked by inputting a preset password.
Generally, in a computer system, a basic input output system program (hereinafter called the BIOS) for controlling various hardware (input and output devices and peripheral devices), such as a keyboard, a display, a floppy disk drive (FDD) and hard disk drive (HDD), is stored in a read only memory (ROM).
Some computer systems are currently known which each has a hard disk having the above-described password lock function, in which the hard disk is set in a password-locked condition by the above-described BIOS program and, when booting the computer system, the user (operator) inputs a password via, for example, the keyboard so that the inputted password is transmitted to the hard disk to unlock the password-locked condition of the hard disk.
The control process of such a conventional computer system (information processing apparatus) in accordance with a CPU (BIOS) when supplying electric power to the computer system will now be described using a flowchart (steps H1–H6) of FIG. 9 of the accompanying drawings of the present application with reference to FIG. 6.
FIG. 6 is a sequence diagram illustrating how to control the hard disk when booting the computer system.
When electric power is supplied to the computer system by, for example, turning a power switch on, a starting process for initializing a system controller, DRAMs and various other devices in the computer system is performed by CPU (BIOS) (step H1). At that time, the BIOS program transmits an INITIALIZE COMMAND to the hard to initialize the hard disk as shown in step B1 of FIG. 6.
Then, CPU discriminates whether the password lock setup of the hard disk is enable or disable (step H2), and if it is disable (see the NO route of step H2), CPU continues the starting process of the computer system (step H6) and then starts an operation system program (OS) and application programs.
If the password lock setup of the hard disk is enable (see the YES route of step H2), BIOS executes displaying on the screen of a display device a direction asking the operator to input a password and waits for input of a password by the operator (step H3).
Now when the operator inputs a password using the keyboard as shown in steps B2–B3 of FIG. 6, BIOS transmits the inputted password to the hard disk by an UNLOCK COMMAND (F2h). The hard disk then collates the inputted password with the password (step H4). If the operator inputs a correct password, namely, if the inputted password coincides with the password previously set in the hard disk (see the YES route of step H4), the password-locked condition of the hard disk is then unlocked (step H5).
Then, BIOS continues the starting process of the computer system (step H6) and further reads the OS, which is stored in the hard disk, to execute a starting process by this OS.
At that time, BIOS transmits a FREEZE COMMAND (F5h) to the hard disk. This FREEZE COMMAND (F5h) is a command for inhibiting any change of the password and any change of setup of the password lock function since then until supply of power to the hard disk is disconnected.
If the inputted password does not coincide with the preset password (see the NO route of step H4), namely, the operator inputs a wrong password in step B3 of FIG. 6, the password-locked condition of the hard disk will not be unlocked and BIOS will continue the starting process of the computer system (step H6), during which the OS stored in the hard disk cannot be read out and hence the starting process in accordance with this OS cannot be executed.
If the operator has inputted a wrong password when the power switch of the above-mentioned conventional computer system is turned on, the password-locked condition of the hard disk will not be unlocked as BIOS continues the starting process of the computer system. Alternatively, if the operator has inputted a wrong password, steps H3 and H4 may be repeated until a correct password is inputted.
In another alternative, a password for unlocking the password-locked condition of the hard disk may be common with that of the computer system; if the operator has inputted a wrong password, the starting process of the computer system will not be continued.
Modern computer systems have the power saving function of reducing power consumption of the computer system by temporarily halting supply of power to the running programs and devices when a power saving switch (such as a suspend switch or a power switch) is turned on or when no further input has been made from a mouse or a keyboard for more than a predetermined time period.
Generally, for a power saving mode in a computer system, there have chiefly been used a suspend method of reducing power consumption to the running programs and devices and a save-to-disk (hibernation) method for storing the contents of a main memory into the hard disk and then shutting off power supply to most of devices. In these individual power saving modes, power supply to the hard disk also is temporarily halted.
The computer system in a power saving mode resumes or restores its normal operating condition in response to an input from outside via a mouse or a keyboard, a receipt of data via a modem or a receipt of a LAN magic packet.
Assuming that supply of power has again been connected to the hard disk according to the resume process after once disconnected according to the power saving mode, the hard disk will be in password-locked condition so that it is impossible to have access to data stored on the hard disk until the password-locked condition of the hard disk is unlocked by inputting a preset password.
The control process of the conventional computer system (information processor) in accordance with CPU (BIOS) when suspending to or resuming from the power saving mode will be described using a flowchart (steps A1–A11) of FIG. 10 with reference to FIGS. 7 and 8.
FIG. 7 is a sequence diagram illustrating control of the hard disk in accordance with BIOS when shifting to the power saving mode (suspend) of the computer system, and FIG. 8 is a sequence diagram illustrating control of the hard disk in accordance with BIOS when resuming from the power saving mode of the computer system.
In the booted computer system, it starts suspending when a power saving switch (such as a suspend switch or a power switch) is turned on or when no further input has been made from a mouse or a keyboard for more than a predetermined time period. CPU (BIOS) firstly transmits an IDENTIFY DRIVE COMMAND (ECh) to the hard disk to request for transmission of information representing the condition of the hard disk, as shown in step C1 of FIG. 7.
Upon receipt of this IDENTIFY DRIVE COMMAND (ECh), the hard disk transmits CONFIGURATION INFORMATION representing the condition of the hard disk, e.g., whether or not setting of a password-locked condition is effective, as shown in step C2 of FIG. 7.
Upon receipt of this CONFIGURATION INFORMATION, BIOS examines from the CONFIGURATION INFORMATION whether or not a password is set with respect to the hard disk and whether or not the hard disk is locked and stores a condition as the examination result of examination in a memory (step A1).
Then, as shown in step C3 of FIG. 7, BIOS executes a power supply shut-off process for the hard disk and a chip set suspend process as well as a suspend process for CPU and other devices (step A2).
The chip set suspend process is a process for adjusting the timing of various signals of chip set {such as control circuits for timer, interrupt, DMA (direct memory access), memory, etc., RTC (real time clock) and bus interface}.
If the save-to-disk (hibernation) method is substituted for the suspend method as the power saving mode, BIOS executes an additional process for storing the contents (condition of the computer system) of a main memory in the hard disk before shifting to the power saving mode.
The chip set suspend process in the save-to-disk (hibernation) method includes a process for reserving in the hard disk configuration information about adjustment of the timing of various signals for chip set (such as control circuits for timer, interrupt, DMA, memory, etc., RTC, and bus interface, etc.) after temporarily expanding the configuration information on the memory.
After the computer system was shifted to its power saving mode, BIOS discriminates whether or not any input has been made from the mouse or the keyboard and whether the power saving switch (such as a suspend switch or a power switch) has been turned on (step A3) and keeps the computer system in its power saving mode until a further input is made (see the NO route of step A3).
Then, when any input is made from the mouse or the keyboard, when data is received via the modem, when a LAN magic packet is received or when the power saving switch is turned on (see the YES route of step A3), CPU (BIOS) starts a resume process restoring its normal operating condition from the power saving mode (suspend) (step A4).
In addition, BIOS performs starting CPU and a chip set resume process (e.g., adjustment of timing of signals for control circuits, which control the timer, interrupt, DMA, memory, etc., RTC, bus interface and other devices) as well as transmits an INITIALIZE COMMAND to the hard disk to turn on the power supply to the hard disk (step A5), as shown in step D1 of FIG. 8.
If the save-to-disk method (hibernation) is used for the power saving mode, the BIOS performs an additional process for expanding the contents (condition of the computer system) of the main memory, which contents were stored in the hard disk before the computer system has been shifted to its power saving mode. The chip set resume process in this case includes not only a process for expanding configuration information about the chip set on the memory, but also a process for storing necessary information in the chip set.
Then BIOS confirms whether the password lock setup of the hard disk as stored in the memory is enable or disable, and if it is disable (see the NO route of step A6), BIOS executes a resume process for devices other than the hard disk, whereupon BIOS executes various controls in accordance with OS.
On the contrary, if the password lock setup of the hard disk is enable (see the YES route of step A6), BIOS correlates with the memory to confirm whether or not the hard disk has been unlocked from a password-locked condition before the computer system entered the power saving mode (step A7).
If the hard disk has been unlocked before the computer system entered the power saving mode (see the YES route of step A7), BIOS instructs the display unit to display a direction requesting the input of a password in order to unlock the password-locked condition of the hard disk to restore its operating condition before the power saving mode, thereby waiting for input of a password by the operator (step A8).
Now, as shown at step D2–D3 in FIG. 8, if a password is inputted by the operator via, for example, a keyboard, BIOS transmits to the hard disk the password inputted in response to the UNLOCK COMMAND (F2h). The hard disk then collates the inputted password with the password previously set in the hard disk (step A9), whereupon the input password coincides with the password previously set in the hard disk (see the YES route of step A9), BIOS unlocks the password-locked condition of the hard disk (step A10).
After continued booting of the computer system (step A11), BIOS reads out the OS, which is stored in the hard disk, and boots the information processor in accordance with this OS.
At that time, BIOS transmits the FREEZE COMMAND (F5h) at step D4 in FIG. 8. This FREEZE COMMAND (F5h) is a command for inhibiting any change of the password and any change of setup of the password lock function since then until supply of power to the hard disk is disconnected.
On the contrary, if the password inputted by the operator at step D3 in FIG. 8 does not coincide with the previously set hard disk, namely, if the operator has inputted a wrong password (see the NO route of step A9), the password-locked condition of the hard disk cannot be unlocked and hence CPU (BIOS) continues the starting process for the computer system (information processor) (step A11). At that time, BIOS cannot read OS stored in the hard disk and hence booting the computer system in accordance with this OS cannot be achieved.
If the operator has inputted a wrong password during the resume process of the above-mentioned conventional computer system, BIOS continues booting the computer system without unlocking the password-locked condition of the hard disk. Alternatively, if the operator has inputted a wrong password, steps A8 and A9 may be repeated until a correct password is inputted.
In another alternative, a common password may be used for unlocking the password-locked condition of the hard disk and for booting the computer system; if the operator has inputted a wrong password, BIOS may not continue resuming the computer system.
If the password-locked condition of the hard disk has not been unlocked before the computer system enters the power saving mode (see the NO route of step A7), BIOS performs a process of step A11 while keeping the password-locked condition of the hard disk without being unlocked.
However, in the foregoing conventional computer system (information processor), if the password lock function of the hard disk is enable, the hard disk assumes a password-locked condition when supply of power to the hard disk has been discontinued in accordance with the power saving mode (such as the suspend method or save-to-disk method) so that either OS or application software cannot have access to data stored in the hard disk until the previously set password (correct password) has been inputted to unlock the password-locked condition. When the information processor is to restore or resumes its normal operation condition from the power saving mode, the operator must input the password at every resume process to unlock the password-locked condition of the hard disk, which is laborious and time-consuming.
Accordingly, assume that various processes accompanied by access to a hard disk, such as automatic reception of facsimile (reception via a modem), automatic process of application software by a timer, and remote access from network environment (reception of LAN magic packet), are performed with respect to a computer system installed in an unattended environment, e.g., in a remote local area. At that time, if both the password lock function of the hard disk and the power saving function of the computer system are set to be enable, it is impossible to resume the normal operating condition from the power saving mode in response to reception of data or the like.
In this case, if the power saving function of the computer system 10 is set to be disable, it is impossible to reduce power consumption, which is non-economical, and, in the meantime, if the password lock function of the hard disk is set to be disable, it is impossible to inhibit any unfair access to data on the hard disk by an unauthorized third party, which is not high enough in security.